In stereo television receivers it is often desirable to have output terminals which can be coupled to an external power amplifier. In such a situation, it is very desirable that the system be "pop" or "thump" free when the television receiver is turned "on" or "off" with the external power amplifier being "on". This requires that the turning "on" and "off" of the television receiver not introduce any transient conditions producing audible signals.
Audible transients coming through the television output jacks typically have two sources, e.g., whatever is ahead of the output driver and the output driver itself. If the supplies to the output driver amplifier are carefully removed, there will be no audible transients produced. Prior art systems used soft starting regulators to try to keep the unbalance of the power supplies small. Because such soft starting regulators do not track exactly, they must be brought up or down in voltage slowly. A much more rapid power-up or power-down can be had with the circuit disclosed herein by forcing the plus and minus supplies to the output driver amplifier to closely track each other.
The present invention permits a plurality of loads to be coupled to the power supply since the plus or minus supplies will track each other regardless of the number of loads coupled to the power supply or the balance of the loading.